Fiabilitate si Durabilitate - Fiability & Durability No 1/ 2018 Editura “Academica Brâncuşi” , Târgu Jiu, ISSN 1844 – 640X 193 ON THE DURABILITY OF CENTRIFUGAL PUMPS Associate Professor Marius STAN, The Petroleum Gas University of Ploiesti, mstan@upg- ploiesti.ro Abstract Vibration diagnosis has developed rapidly, the practice of applying it proving to be highly effective, along with the development of measurement and signal processing techniques. Vibration diagnosis is preferred, with rare exceptions, to noise diagnosis, which is too much affected by ambient noise sources, requiring either special methods or devices or special measurement conditions. Vibrodiagnose, is one of the applications of fault diagnosis methods through vibration analysis to centrifugal pumps Keywords: centrifugal pump, vibration, noise, spectru 1. Process centrifugal pumps. Causes of use The functional parameters of a pump do not keep its values constant throughout its life. This is explained by the fact that the parts that are part of the pump assembly wear out over time. In the case of centrifugal pumps, the nature of the wear of the parts is of two types: 1. Mechanical; 2. Chemical. Regardless of the nature of the wear, it has the effect of modifying the geometric shapes of the parts, which ultimately reflects the modification of the hydraulic parameters of the pump (flow, pressure, pumping height) The frequently used parts of centrifugal pumps are the most exposed parts, both abrasive and corrosive: • rotor; • labirinţii; • shaft protection bushing; • mechanical sealing; • soft gaskets; • camps. When the unit is switched off for maintenance work, the wear condition of the parts is noted and replaced. 2. Vibrations in centrifums pump operation In the exploitation of machines or installations of the various categories, vibrations may occur which, over a certain limit, lead to shortening the life of the machinery and represent for man often very dangerous polluting factors. In general, [1] the most important parameters of the oscillatory movement A (t) can be considered as: • pulse (ωo) - dependent on initial conditions; • the amplitude - a parameter that characterizes the vibration size; • Effective speed / aceleration - a parameter that highlights the vibration energy; Pump aggregate vibration level, expressed as effective velocity (Vef), is measured at significant pump points (housing, bearing body, etc.).